Known rotatable magnetic tumbler locks for use with magnetic keys generally comprise at least one rotatable magnetic tumbler, whose rotary orientation is adjustable by a magnetic key corresponding to a preselected magnetic code and which is engaged by a contacting element of the magnetic lock.
This type of magnetic lock is known and described in detail, for example, in Austrian patent Nos. 341 901 and 357 430. These and similar locks have rotatable magnetic tumblers whose rotary orientation is set by a magnetic key belonging to it corresponding to a proper magnetic code, whereby in the correct lock opening orientation the rotatable magnetic tumbler can be engaged by a locking element of the lock to permit an opening movement of the bolt.
In the correct rotary orientation of the tumblers, for example, the contacting element can be slid or pushed into a recess or notch in the or each rotatable magnetic tumbler and the sliding motion controls for its part the position of a locking element, which causes the operation of the lock, its locking, or allows rotation of a lock cylinder.
This kind of lock can use, for example, a rotatable lock cylinder or a linearly movable lock slider.
In practice these locks in which rotatable magnetic tumbler apparatuses are used have problems related to the operation of the rotatable magnetic tumblers, as is subsequently described in greater detail below.
Specifically, when the rotatable magnetic tumblers are rotated to a new orientation by the magnetic key, because they have a finite mass, they can undergo pendulum-like oscillations about their desired positions, which may under certain conditions prevent the proper engagement of the contacting element of the magnetic lock with the tumbler, thus preventing proper operation of the lock.
Furthermore with certain particular key magnet configurations an incorrect or false key or even a correct key with dexterous manipulation may operate prior art rotatable magnetic tumbler systems As a result the lock may be opened by the false magnetic key should, for example, the rotatable magnetic tumbler be accidently in the open position just prior to engaging it.